Multi-feature-size electronic structures

ABSTRACT

Methods and apparatuses for an electronic assembly. The electronic assembly has a first object created and separated from a host substrate. The first object has a first electrical circuitry therein. A carrier substrate is coupled to the first object wherein the first object is being recessed below a surface of the carrier substrate. The carrier substrate further includes a first carrier connection pad and a second carrier connection pad that interconnect with the first object using metal connectors. A receiving substrate, which is substantially planar, including a second electrical circuitry, a first receiving connection pad, and a second receiving connection pad that interconnect with the second electrical circuitry using the metal connectors. The carrier substrate is coupled to the receiving substrate using the connection pads mentioned.

FIELD OF THE INVENTION

The present invention relates generally to the field of fabricatingelectronic devices with small functional elements depositing in varioussubstrates and apparatuses comprising these electronic devices.

BACKGROUND OF THE INVENTION

There are many examples of functional elements or components which canprovide, produce, or detect electromagnetic signals or othercharacteristics. An example of using the functional components is usingthem as an array of a display drivers in a display where many pixels orsub-pixels are formed with an array of electronic elements. For example,an active matrix liquid crystal display includes an array of many pixelsor sub-pixels which are fabricated using amorphous silicon orpolysilicon circuit elements. Additionally, a billboard display or ansignage display such as store displays and airport signs are also amongthe many electronic devices employing these functional components.

Functional components have also been used to make other electronicdevices. One example of such use is that of a radio frequency (RF)identification tag (RF ID tag) which contains a chip or several chipsthat are formed with a plurality of electronic elements. Information isrecorded into these chips, which is then transferred to a base station.Typically, this is accomplished as the RF ID tag, in response to a codedRF signal received from the base station, functions to cause the tag toreflect the incident RF carrier back to the base station therebytransferring the information.

Demand for functional components has expanded dramatically. Clearly, thefunctional components have been applied to make many electronic devices,for instance, the making of microprocessors, memories, powertransistors, super capacitors, displays, x-ray detector panels, solarcell arrays, memory arrays, long wavelength detector array, phasedarrays of antennas, or the like. The growth for the use of functionalcomponents, however, has been inhibited by the high cost of assemblingthe functional components into other substrates.

For instance, functional components such as semiconductor chips havingRF circuit, logic and memory have been incorporated into an RF ID tag.The tag also has an antenna, and a collection of other necessarycomponents such as capacitors or battery, all mounted on a substrate andsealed with another layer of material. Often the assembling of thesecomponents requires complex and multiple processes thereby causing theprice of the end product to be expensive. Further, the manufacturing ofthese RF ID tag is costly because of inefficient and wasteful use of thetechnologies and the materials used to make these products under thecurrent method.

Depositing semiconductor chips and other components onto substrateshaving the antenna is complex and tedious. The antenna material can be athin film metal which can be deposited on substrates. Alternatively, theantenna material can also be adhered to the substrates using adhesive.These substrate are large compared to these semiconductor chip. Thesemiconductor chips to be interconnected to the antenna thus must bemade large enough to allow for the interconnection. Because thesemiconductor chips need to be large, material costs are thus high.Further, if there is a defective chip, the whole RF ID tag would bedefective and would not be discovered until the whole assembly iscomplete. Then, the whole RF ID tag is disposed along with other goodcomponents. This is intrinsically wasteful and inefficient.

The functional components may also be incorporated into substrates tomake displays such as flat panel displays, liquid crystal displays(LCDs), active matrix LCDs, and passive matrix LCDs. Making LCDs hasbecome increasingly difficult because it is challenging to produce LCDswith high yields. Furthermore, the packaging of driver circuits hasbecome increasingly difficult as the resolution of the LCD increases.The packaged driver elements are also relatively large and occupyvaluable space in a product, which results in larger and heavierproducts.

Furthermore, large displays such as those for signage purposes areexpensive to make. Large displays are often made out of material withlarge-feature-size patterns that must be connected to integratedcircuits (ICs) with small feature sizes. the This results in expensivepackages that are bulky and expensive.

In general, these functional components include semiconductors that aremanufactured on silicon wafers and then are packaged in thick chipcarriers. These chip carriers, such as leaded chip packages, TapeAutomated Bonded (TAB) carrier or flip chip carriers are bulky andexpensive. Alternatively, integrated circuits incorporating intofunctional micro blocks can be used. These blocks and their functionalcomponents have been invented and disclosed in a copending U.S. patentapplication Ser. No. 09/251,220 which was filed Feb. 16, 1999 by theinventor John Stephen Smith and which is entitled “FunctionallySymmetric Integrated Circuit Die.” This application has been issued asU.S. Pat. No. 6,291,896 on Sep. 18, 2001. This patent is herebyincorporated herein by reference.

SUMMARY OF THE INVENTION

The present invention provides methods and apparatuses for an electronicassembly. According to one embodiment, the electronic assembly has afirst object created and separated from a host substrate. The functionalobject has a first electrical circuitry therein. A carrier substrate iscoupled to the first object wherein the first object is being recessedbelow a surface of the carrier substrate. The carrier substrate furtherincludes a first carrier connection pad and a second carrier connectionpad that interconnect with the first object using metal connectors. Areceiving substrate, which is substantially planar, including a secondelectrical circuitry, a first receiving connection pad, and a secondreceiving connection pad that interconnect with the second electricalcircuitry using the metal connectors. The carrier substrate is coupledto the receiving substrate. This coupling is achieved through couplingsof the first receiving connection pad to the first carrier connectionpad and the second receiving connection pad to the second carrierconnection pad. An electrical connection between the first electricalcircuitry and the second electrical circuitry is established.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of a functional component block.

FIG. 2 illustrates an exemplary embodiment of a carrier substrate havingthe functional components blocks inserted therein.

FIG. 3 illustrates a planar view of an exemplary embodiment of an RF IDtag according to the present invention.

FIG. 4A illustrates a cross-sectional view of an exemplary embodiment ofan RF ID tag according to the present invention.

FIG. 4B illustrates a cross-sectional view of an exemplary embodiment ofan FR ID tag wherein the flexible strap has an additional cover.

FIGS. 5-6 illustrate of an exemplary embodiment of an RF ID tagaccording to the present invention.

FIGS. 7A-B illustrate an exemplary embodiment of a signage displayhaving the IC included in the flexible strap.

FIGS. 8A-B illustrate an exemplary display of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates an exemplary embodiment of an object that isfunctional component block 1. Block 1 has a top surface 2 upon which acircuit element is situated (not shown). The circuit element on the topsurface 2 may be an ordinary integrated circuit (IC) for any particularfunction. For example, the IC may be designed to drive a pixel of adisplay. The IC may also be designed to receive power from anothercircuit for the operation of a passive RF ID tag. Alternatively, the ICmay be designed to receive power from an energy source (e.g. battery)for the operation of an active RF ID tag. In one embodiment, block 1 hasa trapezoidal cross-section where the top of the block is wider than thebottom of the block 1. Block 1 may be created from a host substrate andseparated from this substrate. This method of making block 1 can befound in the method described in copending U.S. patent application Ser.No. 09/251,220 now U.S. Pat. No. 6,291,896 referenced above. This patentis hereby incorporated by reference.

FIG. 2 illustrates an exemplary embodiment in which block 1 is depositedin a recessed region of a carrier substrate 12. Once deposited, theblock 1 is recessed below a surface 32 of the carrier substrate 12. Thesurface 32 of the carrier substrate 12 is the native surface of thesubstrate before any deposition of any other materials on top of thesurface 32. Carrier substrate 12 may be a flexible substrate made out ofplastic, fabric, metal, or some other suitable materials. In a preferredembodiment, carrier substrate 12 is flexible. FIG. 2 shows a planar viewof a web material of carrier substrate 12 having recessed regions orholes 21 therein. These recessed regions or holes 21 may be created by avariety of methods. For example, the regions or holes 21 may be createdby a web wheel, roller, or template, that have protruding structures asdescribed in U.S. patent application Ser. No. 09/270,165, entitled“Apparatuses and Methods for Forming Assemblies” (Docket No.003424.P016) by Jeffrey Jay Jacobsen. This patent application is herebyincorporated by reference. Another method involves using a templatehaving blocks wherein the blocks are pressed into web material makingrecessed regions or holes 21 into the web material of carrier substrate12. (See U.S. patent application Ser. No. 09/270,157, entitled “Methodsfor Transferring Elements From a Template to a Substrate” (Docket No.003424.P009) describing the donor transfer method).

The blocks 1 may be deposited into the recessed regions or holes 21 of acarrier substrate 12 by a method described in U.S. Pat. No. 5,545,291.The block 1 is then being recessed within the carrier substrate 12 andbelow the surface 32 of the carrier substrate 12. The U.S. Pat. No.5,545,291 explained how to assemble microstructures onto a substrate,and it is thus, incorporated herein by reference. This process may bereferred to as FSA (fluidic self assembly) and may be performed with aweb material such as the web material for carrier substrate 12. In oneembodiment, a web material is advanced through a web process apparatus.The FSA process deposits a plurality of blocks onto the web materialwherein the blocks fall into recessed regions found in the web material.

FIG. 2 also shows a planar view of the web material of carrier substrate12 wherein the blocks 1 are seated in the recessed regions or holes 21.In one embodiment, electrical interconnect 30 is deposited onto thecarrier substrate 12 interconnecting the top surface 2 of each block 1to each other. Here, the web material of carrier substrate 12 isadvanced to a further point in the FSA process wherein an interconnectlayer is deposited thereon. The interconnect 30 may be comprised ofconductive polymers, metals (e.g., aluminum, copper, silver, gold,etc.), metal particles, conductive organic compounds, or conductiveoxides.

An insulation layer 31, which is a dielectric material, may be coatedover the area that have the interconnect 30 to prevent short circuitwith other functional components that the carrier substrate 12 may comeinto contact with. The insulation layer 31 insulates the circuitelements within the block 1 as well as the interconnect 30 that connectsone block 1 to another block 1. The insulation layer 31 enables thecarrier substrate 12 to cross over at least one electricalinterconnection (e.g., another interconnect 30 on another substrate, oran antenna loop) without shorting out the whole device.

The interconnect 30 may be flexible interconnect layers (not shown).These interconnect layers may be made with the techniques used to createTape Automated Bonding (TAB) tape interconnections well practiced in thesemiconductor industry. The flexible interconnect layers may be createdfrom one of numerous types of materials which are appropriate for a webtape material which is designed to hold electrically conductiveinterconnect layers. These materials include polyimide tapes on whichare deposited conductive traces of metal. The metal may be depositeddirectly on the tape (e.g. by a blanket deposition) and then patternedby etching, or a photoresist layer may be applied and patterned, leavinggrooves into which metal may be deposited. The interconnect may bepatterned to create an intricate wiring pattern such as row and/orcolumn interconnects for an active matrix display backplane. The actualpatterns will depend on the particular application for these functionalcomponents. The flexible interconnect layer, once created, may beapplied to the carrier substrate 12.

It will be appreciated that the flexible interconnect layer may befabricated in a web process and then aligned with the web material ofcarrier substrate 12 having blocks 1 either in a web process or outsideof a web process. It will be further appreciated that the carriersubstrate may be flexible, planar, or rigid and made in a web process orbatch process. It will also be appreciated that an alignment operation,using conventional techniques, may be necessary to properly align theinterconnect layer 30 relative to the carrier substrate 12 with blockswhen the interconnect layer is coupled to the carrier substrate 12.

In one embodiment, the process of interconnecting the functionalcomponents (e.g., blocks 1) embedded in a substrate (e.g., carriersubstrate 12) uses only a single layer of metalization for interconnectlayer 30. This will reduce the possibility of interlayer shorts on theelectronic devices.

FIG. 3 illustrates an exemplary embodiment of an RF ID tag 300. In thisembodiment, a flexible carrier strap 301 comprising functionalcomponents is coupled to a receiving substrate 310, also comprisingfunctional components. The flexible strap 301 may be the carriersubstrate 12 discussed in FIG. 2 above. The flexible strap 301 comprisesat least one functional component 302. The functional component 302 ismuch like the functional component block 1 of FIG. 1. The flexible strap301 also may comprise other necessary components 303 and 304 such as aresistor, a capacitor or an inductor for completing the necessarycircuitry. Components 303 and 304 may also be manufactured as blocks 1above. Components 302, 303 and 304 may be interconnected, typically,through metal connectors such as metal wires, thin evaporated layer ofconductor material (e.g., Aluminum) or ink containing metals (notshown). The interconnection of all the components can be achieved withthe interconnects 30 discussed above.

Flexible strap 301 further includes at least two carrier connection pads305 and 306. The carrier connection pads 305 and 306 are used to couplethe flexible strap 301 to the receiving substrate 310 (see below). Thecarrier connection pads 305 and 306 are made out of conductivematerials. A conductive adhesive can be used to couple the flexiblestrap 301 to the receiving substrate 310 thereby establishing electricalinterconnections for all of the functional components from the flexiblestrap 301 to those from the receiving substrate 310. In anotherembodiment, the methods called cold swaging or ultrasonic welding which,are well practiced in the field, can be used to couple the flexiblestrap 301 to the receiving substrate 310.

In one embodiment, the receiving substrate 310 includes an antenna 311as a functional component. The receiving substrate 310 may be flexibleand made out of some low cost plastic or some other suitable materialfor the particular application. The receiving substrate 310 ispreferably planar. The antenna 311 may be loops of wire attached to thereceiving substrate 310. The antenna 311 may also be made out of screenprinted conductors such as silver, carbon, or metal that is coupled tothe receiving substrate 310 that has been etched with patterns toreceive the antenna material. The antenna 311 may also be made out oflaminated drawn foil that has an adhesive containing layer which enablesthe antenna to be coupled to the receiving substrate 310 in anyparticular pattern, for instance, loops. At each end of the loops of theantenna 311, there is a receiving connection pad, in this embodiment,receiving connection pads 312 and 313. The receiving connection pads 312and 313 are also made out of conductive materials to establish theconductive connection for all of the functional components from thereceiving substrate 310 to those from the flexible strap 301.

In order to complete the circuitry of the antenna 311, the flexiblestrap 301 is coupled to the receiving substrate 310. The coupling of theflexible strap 301 and the receiving substrate 310 is achieved throughthe attachment of the carrier connection pads 305 and 306 to thereceiving connection pads 312 and 313 as shown by arrows A and B. Theflexible strap 301 can cross over at least one conducting material.Here, the flexible strap 301 crosses the loops of the antenna (FIG. 5).In one example, a conductive adhesive is used to couple all of thecarrier connection pads to the receiving connection pads.

It will be appreciated that the flexible substrate 310 may have otherfunctional components or other circuitries, instead of or in addition tothe antenna 311. For instance, another functional component like blocks1 which may have circuitries designed to drive display pixel electrodes,to draw energy source, to sense external inputs, or to transfer data. Inone embodiment, the total carrier connection pads (such as 305 and 306)is only two even if there are multiple functional components in theflexible strap 301.

FIG. 4A illustrates the cross-sectional view of the embodiment describedin FIG. 3. This figure, however, shows in details that there ispreferably an insulation layer 402 between the metal wires 401 thatinterconnect all of the components on the flexible strap 301 and theantenna 311 on the receiving substrate 310. The insulation layer 402 isa dielectric material that serves to electrically isolate the metalwires on flexible substrate 301 and the antenna 311 on the receivingsubstrate 310. Contacting the metal wires 401 with the antenna or theelectrical circuitry will short-circuit the antenna or other theelectrical circuitry.

In addition, the flexible strap 301 can be covered with a protectedlayer 404 for extra protection (FIG. 4B). The protected layer 404 can bemade out of any flexible material such as polymer or plastic. Theprotected layer 404 can also be transparent or opaque.

The method of fabricating the electronic devices described in FIGS. 3,4A and 4B can be applied to make a wide range of other electronicdevices. The small flexible strap 301 with blocks 1 can be made to bereadily available components that can be used for any particularpurpose. For example, the flexible strap 301 can be used in thefabrication of display components, micro-electro-mechanical structuralelements, or generally, an assembly of sensors or actuators or anassembly of circuit elements. Thus, devices such as flexible antennas,other sensors, detectors, or an array of circuit elements may befabricated using one of the embodiments of the inventions.

Another advantage of the present invention is manufacturing ofelectronic devices that are having radically different feature sizes tointerface or integrate with one another. In order to lower the cost ofmaking electronic devices, blocks 1 are made with very small silicon orother materials suitable for carrying a circuit. Making blocks 1 small,(in the order of tens of micrometers in dimension) optimizes theexpensive technology and the expensive media materials necessary (e.g.,silicon wafer) to fabricate these blocks 1. (See U.S. patent applicationSer. No. 09/251,220 reference above). Making the blocks 1 small alsoenables the functional components to be small, thus, saving materialcost as well as the processing cost. Furthermore, small blocks 1 enablesmall packaging of the silicon material which means more of blocks 1 canbe produced at a higher rate with less materials.

However, integrating these functional micro blocks 1 into coarsematerials such as display components, antenna card, or other largeelectronic components, present problems of interfacing or integratingmaterials of radically different feature sizes. For instance, thesubstrate of a display is typically much bigger than that of the blocks1; or the substrate of an antenna in an RF ID tag is likewise muchbigger than that of the blocks 1. Integrating radically differentfeature size materials together is inherently wasteful of areal space,for instance, leaving die area typically useful for essential componentsunused. In yet another example, electronic components of high densitiessuch as transistors, when integrating with other large components, alsoneed to have high densities to minimize waste. Thus, when making largeelectronic devices, the functional components are often large. This iswasteful to expensive material.

In the present inventions, flexible strap 301 may be viewed as aninterposer which is an intermediate that bridge functional components ofradically different densities together without the waste of materials.With the present inventions, the functional component that is the mostexpensive to fabricate can be made like the blocks 1 which is very smallin dimension. The blocks 1 are then deposited into the flexible strap301, and then integrated with another functional components that can bemade out of a cheaper material or technology. More importantly, we canoptimize the most expensive technology, i.e., the interconnectingtechnology, where it is needed. Using the embodiments according to thepresent invention, the expensive interconnecting technology, (e.g., FSA)is only used in making the flexible strip 301 while the making of theantenna, for example, can be achieved using a lower cost interconnectingtechnology. The expensive processes and materials are thus optimized.

The following example illustrates the size differences for an electricaldevice manufactured with the methods described above. The functionalblock 14 has a total size of 350 μm×500 μm (width×length) with a designfeature size or design rule of 0.5 μm. The flexible strap 301 as a totalsize of 1.5 mm×10 mm with a design feature size of 20 μm. And, thereceiving substrate 311 has the total size of 20 mm×50 mm with thedesign feature size of 250 μm. The design feature size or design rulecan be thought of as a density for each of the components. Theembodiments discussed therefore, enable the integrating and theinterfacing of radically different density electronic devices to eachother without wastes of expensive material and technology.

FIG. 5 illustrates an example of an RF ID tag 500 made using the methoddescribed in FIGS. 3, 4A and 4B. Current art includes RF ID tags, whichare small, nevertheless, contains very limited information due to thesize constraint. Also, current RF ID tags are inflexible because the ICpackagings are rigid and large. Storing more information also means thatthe RF ID tag would have to have more functional components and as aresult, require more interconnections among different functionalcomponents. Placing these many functional components on the samesubstrate is overly expensive and complex, not to mention increasing thechance for short circuit in the system. For a flexible and thin RF IDtag, it is desirable to have the silicon integrated circuitry (IC) besmall and thin. The blocks 1 described above may be used to contain theIC which can then be incorporated into the RF ID tag 500. The RF ID tag500 can be placed on products such as store merchandise as a way tolabel, identify, and track these products.

FIGS. 5 illustrates an example of depositing the all of the functionalcomponents except for the antenna 311 onto the flexible strap 301 andusing the flexible strap 301 to bridge the antenna 311. FIG. 6 is anenlarged view of the flexible strap that is used in the RF ID tag 500.

In a conventional method, the antenna 311 would be deposited onreceiving substrate 310, typically a thick material. The functionalcomponents (not shown) would then be deposited in area 500. Someconductive material would interconnect the functional components to eachother. Then, a strap would bridge one side of the loops of the antenna311 to the other side of the loops of. The strap has no function otherthan to complete the circuit for the antenna 311. Under the current artif there is a defective functional components, that will not be detecteduntil the whole fabrication of the RF ID tag 500 is completed. When thathappens, materials are wasted since the whole RF ID tag is discarded.Furthermore, the alignment of these functional components makes theassembly process complicated and expensive.

In the present embodiment, the functional components would be placed inthe flexible strap 301 and not area 500. The flexible strap 301 wouldserve to bridge one side of the antenna 311 to the other side of theantenna 311. Furthermore, the flexible strap 301 would carry thefunctional components that have particular functions, for instance, toreceive power for the operation of the RF ID tag 500 or to sendinformation to a base station of the RF ID tag base 500.

By using the embodiments of FIGS. 3-6 a low cost technology such asscreen-printing can be used to produce large area elements such as theantenna 311. In one example, the antenna 311 may be printed in massivequantity on some low cost substrate and using a process that requiresless rigorous alignment. The functional component such as the blocks 1to drive the antenna 311 or to send the data from the RF ID tag 500, maybe as described in U.S. patent application Ser. No. 09/251,220 mentionedabove. The blocks 1 are then integrated into the carrier substrate 12with a high precision and more expensive technology such as the fluidicself-assembly. Thus, the small flexible strap 301 can be used to carryall of the essential components that are expensive to manufacture. Theexpensive interconnecting technology is optimized in that all of theessential components are packaged into the flexible strip 301 which isthen coupled to the antenna that would be made out of a lower costinterconnecting technology.

Another example using the flexible strap 301 to integrate with otherfunctional components to make electrical device involves the making of asignage display. FIGS. 7A-7B illustrate a general view of a signagedisplay utilizing the flexible strap 301 of the present invention. Thedisplay system 700 includes a flexible strap 701, which is similar tothe flexible strap 301 described above, a top electrode layer 710, aviewable area 720, and a backplane layer 730.

In a conventional technology, a general display system have itselectronic circuit elements, such as row or column driver circuits,attached to flexible circuits such as TAB tape. The assembly is thenattached to the LCD on one side and a PC board on the other. Anadditional set of circuits is usually added to the second glass orplastic layer. In a passive matrix LCD, the driver circuits are attachedto each glass or plastic substrate; in an active matrix LCD, the drivercircuits are attached to two or four edges on only one of the glass orplastic substrates. These drive circuits provide the electrical controlsignals and data required to form an image on the LCD. While an LCD isused for the example, the same principles apply to other display mediasuch as plasma, electroluminescence, electrophoretic, electrochromic,and the like.

Unlike the conventional method, in one embodiment of the presentinvention, the flexible strap 701 includes at least one integratedcircuit which is embedded in a functional block 702. The functionalblock 702 is manufactured as one of the blocks 1 discussed above. Thefunctional block 702 may be manufactured according to the methoddisclosed in the U.S. patent application Ser. No. 09/671,659, entitled“Display Devices and Integrated Circuits” which was filed on Sep. 27,2000, by inventors Roger Green Stewart, et. al., (Docket No.03424.P028). This patent application is incorporated by referenceherein.

In this embodiment, the functional block 702 is interconnected to eightoutput pads, 703 a, 703 b, 703 c, 703 d, 703 e, 703 f, 703 g, and 703 h.Each of these output pads is responsible for driving a particularsegment of the display system. And, each of the segment displays aparticular image of the signage display. The functional block 702 mayalso include an output pad 705 for a ground signal, or other necessaryfunction for an integrated circuit.

Each of these output pads 703 a, 703 b, 703 c, 703 d, 703 e, 703 f, 703g, and 703 h functions like those carrier connection pads 305 and 306.In essence, these pads establish electrical connections between theintegrated circuit included in the functional component 702 and thefunctional components on the display. In one example, the output pad 703g may be used to establish the electrical connection with the portion ofthe top electrode layer 710 that is responsible for controlling the“Jones Product” segment of the display system 700. Similarly, the outputpad 703 e may be used to establish the electrical connection with theportion of the top electrode layer 710 that is responsible forcontrolling the “Creations” segment of the display system 700. In otherwords, the output pads 703 a, 703 b, 703 c, 703 d, 703 e, 703 f, 703 g,and 703 h all establishes electrical connections with the top electrodelayer 710 that in turn drives the segments of the display system 700.

In a preferred embodiment, the flexible strap 701 is coupled to thebackplane layer 730 of the display system 700. To affix the flexiblestrap 701 to the display system 700, a thin layer of nonconductiveadhesive may be coated over the carrier substrate 704. In one example,the adhesive would be coated over the all of the area that do not havethe output pads 703 a, 703 b, 703 c, 703 d, 703 e, 703 f, 703 g, and 703h. Thus, the flexible strap 701 may be affixed to a surface such as thebackplane layer 730 while the electrical function of the output pads 703a, 703 b, 703 c, 703 d, 703 e, 703 f, 703 g, and 703 h would not beblocked by the adhesive layer. These outputs pads therefore, would beable to establish the necessary electrical connections with the topelectrode layer 710.

In another embodiment, the output pads 703 a, 703 b, 703 c, 703 d, 703e, 703 f, 703 g, and 703 h are all made out of conductive adhesive suchthat when affixed to the top electrode layer 701, these pads canestablish both the mechanical as well as the electrical contact to theelectrode layer 701.

It will be appreciated that the number of the output pads depends on theparticular applications or the displays. The number of the output padsmay be more or less than eight output pads for each functional componentblock. Further, larger signage display can also be made using theexamples discussed above. For instance, when the signage displayrequires more segments or portions for larger images, more functionalblocks 1 can be incorporated into the flexible strap 701.

In a preferred embodiment, the flexible straps 701 a, 701 b, 701 c, and701 d are coupled to the backplane layer 730 of the display system700-2. A thin layer of nonconductive adhesive may be coated over thecarrier substrate 704 a, 704 b, 704 c, and 704 d. The adhesive would becoated over the all of the area that do not have the output pads. Thus,the flexible straps 701 a, 701 b, 701 c, and 701 d maybe affixed to thebackplane layer 730 and the adhesive layer would not block theelectrical function of the associated output pads. These output padstherefore, would be able to establish the necessary electricalconnections with the top electrode layer 710 for the display 700.

FIG. 8A shows an overview of a display system 800, which can be thesignage display 700 in FIGS. 7A-7B. FIG. 8A illustrates a planar view ofthe display system 800 and FIG. 8B illustrates a cross-sectional view ofthe display system 800. The display system 800 comprises of a carriersubstrate 802, which includes integrated circuits, for example, block 1,for driving the display. In one embodiment, carrier substrate 802 isflexible and small. For example, the carrier substrate 802 isconsiderably smaller than the receiving substrate 801. The carriersubstrate 802 is coupled to pixel electrodes 801A-801D on a receivingcarrier substrate 801 through the couplings of connection pads, forinstance connection pad 806A to 807A, connection pad 806B to 807B,connection pad 806C to 807C, and connection pad 806D to 807D. Thesecouplings would enable the integrated circuit to drive the pixelelectrodes 800A-800D in the display system 800. The display system 800also comprises insulation layer, display material, and counter electrodeor cover glass electrode. They are discussed in details below.

FIG. 8B shows a cross-sectional view of the display system 800 accordingto one embodiment of the present invention. The display system 800includes a carrier substrate 802, which has receiving openings forfunctional components such as integrated circuits 802A, 802B, and 802C.The carrier substrate 802 is made using the embodiment discussed abovefor flexible strip 301 in FIG. 3. Similar to the embodiments discussedabove, the functional components once coupled to the carrier substrateare recessed within the carrier substrate and below the native surfaceof the carrier substrate. The carrier substrate 802 also includescarrier connection pads 806A-D, which establish mechanical as well aselectrical connections with the receiving substrate 801.

The receiving substrate 801 can be made using a coarse technology andsome coarse materials for making signage display. The display system 800includes a receiving substrate 801 which further comprising pixelelectrodes 801A-801D. The receiving substrate 801 also comprisesreceiving connection pads 807A-D. The receiving connection pads 807A-Dare interconnected with the pixel electrodes 801A-D and thus, whencoupled to the carrier connection pads 806A-D, establish mechanical aswell as electrical connections with the carrier substrate 802. Similarto the embodiments discussed above, the carrier substrate 802 can crossover at least one electrical interconnection on the receiving substrate801 without damaging or shorting the pixel electrodes on the receivingsubstrate 801. The carrier connection pads 806A-D are alsointerconnected with the ICs 802A, 802B and 802C. When all the necessaryconnections are established, the ICs will then drive the pixel electrodeof the signage display 800.

The integrated circuits 802A, 802B, and 802C are display drivers in oneembodiment. When proper mechanical and electrical connections areestablished, these integrated circuits will drive the pixel electrodesin the display system 800.

The carrier substrate 802 may be made out of a metal, foil, or flexibleplastic material. An insulating layer 805 maybe attached to a topsurface of the carrier substrate 802. In such an example, the insulatinglayer 805 has a plurality of openings through which electricalinterconnections can be established (e.g., vias through which carrierconnection pads 806A-D interconnect with receiving connection pads807A-D).

A layer 808 may be provided on top of the pixels electrodes and theconductive signals electrodes in order to insulate these parts from thedisplay media material 803 which may be a nematic liquid crystal, anelectrophoretic display material, a polymer dispersed liquid crystalmaterial, an organic light emitting diode material, a cholesteric liquidcrystal material, an electrochromic material, a particle-based material,a thin-film electroluminescent material, or other known displaymaterials which can be driven by pixel electrodes or other types ofdisplay materials which may be controlled by electrodes. A counterelectrode or cover glass electrode 804 is typically a thin layer oftransparent indium tin oxide which is deposited upon a cover glass 900which is transparent. Spacers 809 are attached to the layer 808 and tothe cover glass 900 to provide a desired spacing between the counterelectrode 804 and the layer 808.

It can be seen from FIGS. 8A-8B that carrier substrate 802 acts as aninterposer that integrates or interfaces two radically different featuresized electrical devices to each other (e.g., integrating the microdisplay drivers to the large signage display). The methods describedabove allow the ICs to be manufactured in the order of sub-micrometerdensity. The methods above then enable the integration of thesubmicrometer ICs to a much coarser and larger display. Using thismethod, the ICs do not need to be made large in order to facilitate thecoupling of the ICs into a large display panel. Expensive materials andtechnologies are thus optimized. This provides for greatly reducedmanufacturing costs and improved yield and efficiency in themanufacturing process.

It will be appreciated that the display system 800 illustrates oneexemplary embodiment of making display according the present invention.Displays according to the present invention may be used to fabricatedisplays with liquid crystals, polymer dispersed liquid crystal,electroluminescent (EL) materials, organic light emitting diodes(OLEDs), up and downconverting phosphor (U/DCP), electrophoretic (EP)materials, or light emitting diodes (LEDs).

Fabrication of display panels is well known in the art. Display panelsmay be comprised of active matrix or passive matrix. Active matrixpanels and passive matrix panels may be either transmissive orreflective.

Liquid crystal displays (LCDs), for example, display system 800, canhave an active-matrix backplane in which thin-film transistors areco-located with LCD pixels. Flat-panel displays employing LCDs generallyinclude five different components or layers. A light source, a firstpolarizing filter that is mounted on one side of a circuit panel onwhich the thin-film transistors are arrayed to form the pixels such aspixels 801A-801D. A filter plate containing at least three primarycolors are aligned with the pixels (for color displays), and a secondpolarizing filter. A volume between the circuit panel and the filterplate is filled with liquid crystal material, for instance, layer 803.This material will rotate the polarized light when an electric field isapplied between the thin-film transistor circuit panel and a electrodesaffixed to the filter plate or a cover glass. Thus, when a particularpixel of the display is turned on, the liquid crystal material rotatespolarized light being transmitted through the material so that it willpass through the second polarizing filter. Some liquid crystalmaterials, however, require no polarizers. LCDs may also have a passivematrix backplane which is usually two planes of strip electrodes whichsandwich the liquid crystal material. However, passive matricesgenerally provide a lower quality display compared to active matrices.U/DCP and EP displays are formed in similar fashion except the activemedium is different (e.g., upconverting gas, downconverting gas,electrophoretic materials).

EL displays have one or more pixels that are energized by an alternatingcurrent (AC) that must be provided to each pixel by row and columninterconnects. EL displays generally provide a low brightness outputbecause passive circuitry for exciting pixel phosphors typicallyoperates at a pixel excitation frequency that is low relative to theluminance decay time of the phosphor material. However, an active matrixreduces the interconnect capacitance allowing the use of high frequencyAC in order to obtain more efficient electroluminescence in the pixelphosphor. This results in increased brightness in the display.

LED displays are also used in flat-panel displays. LEDs emit light whenenergized. OLEDs operate like the LEDs except OLEDs use organic materialin the formation of the light emitting device.

The displays discussed above are particularly useful for signagedisplays used in airport terminal, commercial signage display, orbillboard displays. These types of displays are typically large and themanufacturing of the display panel is relatively cheap due to the factthat they employ a less rigorous technology with large feature sizes.However, the integrated circuit needed to drive these types of displaysare expensive to make and have small feature sizes. The method of thisinvention allows the manufacturers to make the IC very small and stillconnect them to the large signage display.

The flexible strap 301 is particularly crucial for integrating andinterfacing electronic devices of radically different feature sizes.Integrating and interfacing the blocks 1 to a coarse and large displayrequires the blocks 1 to be large enough in order for the integratingand the interfacing to be feasible. However, to minimize cost in makingthe IC, the blocks 1 are very small in feature size, for example, theblocks 1 have a densities in the vicinity of sub-micrometer. The signagedisplay is typically in the order of 100-250 micrometer in density. Oneway to efficiently integrating and interfacing the signage display tothe blocks 1 is through using the carrier substrate discussed above forthe flexible strap 301.

The following example illustrates the size differences for a signagedisplay manufactured with the methods described above. The functionalblock 1 has a total size of 350 μm×500 μm (width×length) with a designfeature or design rule of 0.5 μm. The carrier substrate 802 has a totalsize of 10 mm×10 mm with a design feature of 20 μm. And, the receivingsubstrate 801 has the total size of 20 in×50 n with the design featureof 250 μm. The carrier substrate is thus about one order of magnitudedifferent from the functional block 1 and an order of magnitudedifferent from the signage display. The embodiments discussed therefore,enable the integrating and the interfacing of electronic devices havingradically different density, feature size, and total size, to each otherwithout wastes of expensive material and technology.

An electrical device made according to the embodiments of the presentinvention also has an advantage of being multi-feature-size. Forinstance, the carrier substrate 12 may have a feature size (design rule)that is at least five times larger than the block 1. The carriersubstrate 12 also has a feature size that is at least five times smallerthan the receiving substrate 310.

The functional block 1 can be packaged in a flexible strap, the carriersubstrate discussed above. Flexible packaging also means that thesesignage displays can be made flexible which is extremely useful for manypurposes. It also means that the sign can be very thin, owing to thethin dimension of the flexible strap.

An electrical device made according to the embodiments of the presentinvention also has all of the electrical circuitry in the functionalcomponents and the necessary interconnections, (e.g., the firstinterconnection and the second interconnection) are all essentially incoplanar to each other. As can be seen from FIG. 3 and FIG. 5, when thewhole device is assembled together, all of the components mentionedabove are essentially in one plane field. Alternatively, all of theelectrical circuitry in the functional components and the necessaryinterconnection, (e.g., the first interconnection and the secondinterconnection) each forms a plane that is separated from one anotherby less than ten micrometers. Therefore the planar electrical circuitryon the functional component, the planar first interconnection on thecarrier substrate, and the planer second interconnection on thereceiving substrate are all coplanar with each other such that theirplanes are typically separated by less than 10 micrometers.

We claim:
 1. An electronic assembly comprising: a first object createdand separated from a host substrate, said first object having a firstelectrical circuitry therein; a carrier substrate coupling to said firstobject, said carrier substrate further comprising a first carrierconnection pad and a second carrier connection pad that interconnectwith said first object using metal connectors, at least a portion ofsaid first object being recessed below a surface of said carriersubstrate; a receiving substrate including a second electrical circuitrywhich is substantially planar, said receiving substrate furtherincluding a first receiving connection pad, and a second receivingconnection pad that interconnect with said second electrical circuitryusing said metal connectors, said first receiving connection pad couplesto said first carrier connection pad and said second receivingconnection pad couples to said second carrier connection pad providingan electrical connection between said first electrical circuitry andsaid second electrical circuitry; and at least one second object, atleast a portion of said second object being recessed within said carriersubstrate and being interconnected to said first to said first objectusing said metal connectors.
 2. An electronic assembly as in claim 1further comprising at least one third object, said third object beingcoupled to said receiving substrate and being interconnected to saidsecond electrical circuitry using said metal connectors.
 3. Anelectronic assembly comprising: a first object created and separatedfrom a host substrate, said first object having a first electricalcircuitry therein; a carrier substrate coupling to said first object,said carrier substrate further comprising a first carrier connection padand a second carrier connection pad that interconnect with said firstobject using metal connectors, at least a portion of said first objectbeing recessed below a surface of said carrier substrate; a receivingsubstrate including a second electrical circuitry which is substantiallyplanar, said receiving substrate further including a first receivingconnection pad, and a second receiving connection pad that interconnectwith said second electrical circuitry using said metal connectors, saidfirst receiving connection pad couples to said first carrier connectionpad and said second receiving connection pad couples to said secondcarrier connection pad providing an electrical connection between saidfirst electrical circuitry and said second electrical circuitry; andwherein said electronic assembly is a multi-feature-size structure inwhich said carrier substrate is at least five times larger in featuresize than said first object and wherein said carrier substrate is atleast five times smaller in feature size than said receiving substrate.4. An electronic assembly comprising: a first object created andseparated from a host substrate, said first object having a firstelectrical circuitry therein; a carrier substrate coupling to said firstobject, said carrier substrate further comprising a first carrierconnection pad and a second carrier connection pad that interconnectwith said first object using metal connectors, at least a portion ofsaid first object being recessed below a surface of said carriersubstrate; and a receiving substrate including a second electricalcircuitry which is substantially planar, said receiving substratefurther including a first receiving connection pad, and a secondreceiving connection pad that interconnect with said second electricalcircuitry using said metal connectors, said first receiving connectionpad couples to said first carrier connection pad and said secondreceiving connection pad couples to said second carrier connection padproviding an electrical connection between said first electricalcircuitry and said second electrical circuitry; wherein said carriersubstrate is flexible, and wherein said electronic assembly is amulti-feature-size structure in which said carrier substrate is at leastfive times larger in feature size than said first object and whereinsaid carrier substrate is at least five times smaller in feature sizethan said receiving substrate.
 5. An electronic assembly comprising: afirst object created and separated from a host substrate, said firstobject having a first electrical circuitry therein; a carrier substratecoupling to said first object, said carrier substrate further comprisinga first carrier connection pad and a second carrier connection pad thatinterconnect with said first object using metal conductors; a receivingsubstrate including a second electrical circuitry which is substantiallyplanar, said receiving substrate further including a first receivingconnection pad, and a second receiving connection pad which interconnectwith said second electrical circuitry using said metal conductors, saidfirst receiving connection pad couples to said first carrier connectionpad and said second receiving connection pad couples to said secondcarrier connection pad providing an electrical connection between saidfirst electrical circuitry and said second electrical circuitry; andsaid carrier substrate crosses over at least one of said metalconductors on said receiving substrate and is at least five times largerin feature size than said first object and at least five times smallerin feature size than said receiving substrate.
 6. An electronic assemblyas in claim 5 wherein said electronic assembly is a multi-feature-sizestructure in which said carrier substrate is at least ten times largerthan said first object and wherein said carrier substrate is at leastten times smaller than said receiving substrate.
 7. An electronicassembly as in claim 6 wherein said carrier substrate couples to saidfirst object through a fluidic self-assembly process.
 8. An electronicassembly as in claim 7 wherein said carrier substrate is flexible.
 9. Anelectronic assembly comprising: a first object created and separatedfrom a host substrate, said first object having a first electricalcircuitry therein; a carrier substrate coupling to said first object,said carrier substrate further comprising a first carrier connection padand a second carrier connection pad that forms a first interconnectionwith said first object using metal conductors; a receiving substrateincluding a second electrical circuitry which is substantially planar,said receiving substrate further including a first receiving connectionpad, and a second receiving connection pad that forms a secondinterconnection with said second electrical circuitry using said metalconductors, said first receiving connection pad couples to said firstcarrier connection pad and said second receiving connection pad couplesto said second carrier connection pad providing an electrical connectionbetween said first electrical circuitry and said second electricalcircuitry; and said first electrical circuitry, said firstinterconnection, and said second interconnection are essentiallycoplanar, wherein each of said first electrical circuitry, said firstinterconnection, and said second interconnection forms a plane and eachof said planes is separated from one another by less than tenmicrometers.
 10. An electronic assembly as in claim 9 wherein saidcarrier substrate is flexible.
 11. An electronic assembly as in claim 1wherein said second electrical circuitry is an antenna.
 12. Anelectronic assembly as in claim 3 wherein said second electricalcircuitry is an antenna.
 13. An electronic assembly as in claim 4wherein said second electrical circuitry is an antenna.
 14. Anelectronic assembly as in claim 5 wherein said second electricalcircuitry is an antenna.
 15. An electronic assembly as in claim 9wherein said second electrical circuitry is an antenna.